Humility...a sign of weakness?

Most of the leaders I've observed and worked with over the years have been concerned with appearing strong and in command of their teams, their position, and their lives.

Some of them were naturally arrogant and some developed an arrogant posture to seem tough and strong. Some even took to bullying others. Sometimes the bravado appeared to be a thinly veiled attempt to cover up a fear of inadequacy.

There were a few leaders who were different from the rest. They were calm and self-assured instead of seeming full of themselves. They were even deferential with others, knowing that they weren't special, but just another member of the organization who was trying to do their best. They respected those around them, both above and below, for the contributions they made, knowing that all team members are capable of sharing.

Instead of an air of cockiness, these people adopted one of humility. They knew they weren't perfect, but they also knew they were competent. When they made a mistake, they didn't try to deflect the responsibility on someone else. When they messed up, they stood up and were accountable; then they worked to correct the problems and make modifications to ensure the problems didn't reoccur.

Leaders should always want to deal with issues from a position of strength. So, what does that position of strength look like? Is it all about strutting around and looking superior or can it be quiet confidence rooted in maturity, experience, and self-awareness?

So I ask, is humility a sign of weakness...or is it a sign of strength?